I have a few personal stories to share on this topic. I'm pretty addicted to caffeine (through coffee), 2 huge cups in the morning, sometimes another larger cup at noon and then on the weekends had in our Saturday "treat" of a weekend Venti Latte. I wake up pretty much with a head ache until I drink a cup. (I need to cut back but thats another topic)

So here are my "3" race stories from when I have tired to cut it out and actually stuck to it. I think it is in most cases/times such a huge benefit to do I wish I could actually stick to my plan of doing it before every marathon.

2009--I cut it out for 7-10 days before the Columbus Marathon, I brought it back in on race morning like the strategy I was following said to do and had terrible stomach issues. I DID PR but I had "2" stops so looking back on the day now with it still being my PR, I'm left wondering how fast could I have ran without the stops...I ran 2:29 and think I could have slipped under 2:26 without the stops/problems.

2010--I wanted to do it for Boston Marathon so I tried testing it for tuneup Half Marathon while in Miami, Fla. My goal for the race was just to stick to Boston Goal Marathon Pace which isn't always easy even for a half marathon when in hard training and no taper...long story short, it worked perfectly and I ran my easiest MP workout of the entire build up with no stomach problems this time. (I couldn't stick to the plan before Boston and drunk coffee the entire week before the race)

2011--I was having some troubles that I think was from getting in too much caffeine on a daily basis..so in August I cut coffee out during the week but would drink it during the weekends....this method seemed to be pretty successful as well as I went from a struggle fest 1:14 half in July to 1:10 pre-marathon tuneup half marathon in Oct. During that stretch from Aug-Oct I would cut it out all week and then drink it on weekends. Seemed to work even better for getting a boost from it then the 1 time cut of 7-10 days.

I'm 50/50 on a June Marathon this summer if I can remain healthy, if I do I'm sure to "try" and do the depletion phase again as it I think it has HUGE benefits for people that consume larges amounts of caffeine on a daily basis. Be prepared to feel like crap during the depletion as far as head aches, etc. My legs actually never feel bad during the depletion.